The solar spectral irradiance since 1700

The change in the irradiance spectrum of the Sun from 1700 to the last sola r minimum is determined and compared to the change in the spectrum between activity minimum and maximum. For this purpose we have used detailed model flux spectra of solar magnetic features. Also, time-series of the solar spe ctral irradiance since 1700 in different wavelength bands are reconstructed . We expect that these reconstructions are more accurate than previously pu blished ones, although they suffer (like all reconstructions of solar irrad iance on such time-scales) from uncertainties in our knowledge of the evolu tion of the solar network with time.